Lawn mower still won't start after checking the usual suspects, is it finished?

Comer1

I have a very old (23 years) Honda lawn mower, but it's still going very well, if burning a little oil. It was working perfectly last Tuesday, when I tried to use it yesterday, it wouldn't start. Only thing I did differently last Tuesday was to have it on it's side a bit longer than usual to clean it.

What I've tried:

Drained the petrol and put in fresh petrol

Checked that the spark is sparking, it is.

Removed the carburettor and gave it a thorough clean and I'm almost 100% sure all the jets are clear.

It still seems to me that the spark plug is not getting any petrol. When I remove it, I can't get the smell of petrol from it. I have ordered a new carburettor from Amazon (only €28 including gaskets). Am I wasting my time, is there anything else I can try. Only thing I did notice is the gaskets either side of the carburettor are not great, would that make a difference.

Thanks

The Continental Op

Fuel filter? If plug is completely dry when you take it out is their fuel in the float chamber. Then if there is did you carefully clean the needle valve thats connection to the float. You can check if no fuel getting through is a problem by taking the plug out and putting a drop of fuel in throught the plug hole then replacing the plug, cranking should then fire a couple of times before dieing again, althought sometimes that will get an old mower going.

• Flagged as this might be better in Gardening?

Comer1

There is fuel in the float chamber which is after the fuel filter so I don't think that's the problem. It seems to me that the fuel is not getting from the float chamber to the spark plug. I'm absolutely certain that the needle valve is clear. The only valve I'm not 100% sure is clear is the internal valve under a screw on top of the carburettor.

I'll try your tip with fuel in through the spark plug hole now, thanks.

Comer1

Putting a drop of petrol in through the spark plug hole didn't get it to start, even for a few seconds.

I've attached a video checking the compression in the engine. I clamped the handle that engages the blade in the on position and recorded this video. Does it look like that's the problem?

https://youtube.com/shorts/QSYpZoEDJDo?feature=share

The Continental Op

That does look rather knackered with no compression. However there is a mechanism in all small engines that reduces the compression to make them easy to turn over to start. Honda have there automatic mechanical decompression system, https://engines.honda.com/why/technology. So hard to be sure lack of compression is the problem.

The petrol direct into the cylinder is to see if the spark plug is working. Evidently its not?

The Continental Op

I'm sure you have tried all these things here https://canberradiamondblade.com.au/small-engine-troubleshooting/ but I found reading it through useful as it reminded me of the flywheel key. Never had to replace one on a Honda but used to have to do it very often on B&S engines. With the key sheared the timing is out completely and the machine won't start. Check for youtube videos there are loads but interesting mostly of B&S engines and I couldn't find one for a Honda so suspect that isn't your problem if other people aren't seeing the same one.